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Sun Feb 12, 2012 11:29 am

I have a '73 type 1 transmission in my '66 type 2. Had it rebuilt in California about fifteen years ago, have traveled across country with it three times (Cal to Fla & back) with no issues.

Lately, I get a high pitched whine above 4000 rpm or 70 mph which can be felt in the shift knob. I figure it's most likely a shift fork.

Any advice from the more experienced about replacing it myself would be appreciated. I have a '74 transmission which I'm installing today so I can drive while working on the older one. Had a '74 when I bought the car but the gearing was too high and it popped out of 4th gear unless I held the shifter in place. Used it for a year in the Big Sur mountains but when it was time to replace I went with the '73. Besides, who needs 4th gear when 3rd will take you to 70 mph? I run 15" wheels with low profile fat tires.

I'm an experienced machinist and have repaired many motorcycle transmissions - I'm confident I can do this without a shop's help. Is there any trick to getting it open or getting the shift forks off that I need to know?

Sun Feb 12, 2012 12:01 pm

How long has it been since you chaged the gear oil in the trans? It should be changed every 30,000 miles.

The Bentley repair manuals have a complete chapter on rebuilding a VW transaxle. It also tells you what special tools you need.

http://vwparts.aircooled.net/VW-Bentley-Manuals-s/164.htm

Sun Feb 12, 2012 12:56 pm

I have a bentley manual, but it matches the body, '66, rather than the transmission. I changed the oil a year ago, about 10,000 miles. The noisy one is out now and I'm about to install the spare.

Sun Feb 12, 2012 2:13 pm

Harleyelf wrote: Lately, I get a high pitched whine above 4000 rpm or 70 mph which can be felt in the shift knob. I figure it's most likely a shift fork.
Your logic escapes me. Whining is caused by a bad part that is turning. Shift forks don't move, so therefore they can't cause any noise.

Does it make the noise above 4k rpm in all gears? Or only above 70mph?

Sun Feb 12, 2012 2:18 pm

All gears, worst in high. And shift forks in every transmission I've ever disassembled push a turning gear into a neighboring gear so the dogs in the unsplined gear engage with the slots in a splined one. When they get bent they no longer ride in the groove provided, but have unwanted contact with the side of their groove. Once I get inside it I'll have a better idea of what's rubbing.

Sun Feb 12, 2012 2:30 pm

VW shift forks don't bend. The steel ones are strong enough that they don't bend, and the brass ones are weak enough that they break. Brass only exists in some years for 1-2 fork only. A fork rubbing on the side of the groove of the slider won't make any noise, it's well lubricated.

Your problem is somewhere in the axles. Bad wheel bearing, diff bearing, R&P, R&P bearing, or mainshaft bearing.

Sun Feb 12, 2012 2:53 pm

That would have been my first thought if it didn't also happen in neutral. The '74 was quiet when I ran it in my Ghia, it'll give me the leisure time to find out what's up with the '73. I only bought it (the '74, from a sun bug with 50K miles) and put it in the Ghia because the PO of the Ghia had filled its original transmission with wheel bearing grease. Heated it up, drained the grease, replaced it with good gear lube, and it works great. It had a shifting issue that traced to the shift lever assembly and went away with a Hurst shifter, so I put it back in the car and it's been good to me for the last eight years. I've had the bus for twenty years.

Sun Feb 12, 2012 7:31 pm

If your confident you can do this without shops help, why are you asking a bunch of arm chair, computer loving, hicks?

Sun Feb 12, 2012 7:41 pm

I'm confident I can do this with proper research and manuals. I know the difference between a wheel or main bearing noise and a transmission vibration. I was hoping somewhere on this forum to find a real mechanic who had done the job before and could share a helpful hint or two. The rubber pads between the cradle and the bell housing had separated from their bolts - the right CV joint has rubbed the cradle mount and that may be the 70mph noise but there is still the vibration in the gear shift knob that gets audible from the transmission at 4000 rpm. I've had this bus for twenty years and lived in it for three - it is important to me that I know every nut, bolt, and issue it has. And since I have a spare transmission, if I really muck it up I can always toss it and use the '74 forever.[/img]

Sun Feb 12, 2012 7:56 pm

bad bearing in the trans. Not a fork. I guess the pinion bearing.

Sun Feb 12, 2012 8:15 pm

Now that's a useful comment. Thank you very much.

Sun Feb 12, 2012 9:11 pm

Harleyelf wrote: Now that's a useful comment. Thank you very much.

Cool!... Looks like you joined on my birthday!
Some bearings are easy to replace.
If the sound gets higher pitched with speed, it has to be part of the final drive. a common bearing to fail is the front mainshaft bearing because its the first to starve for oil. Its not hard to replace either.

Sun Feb 12, 2012 9:22 pm

Bruce wrote: Your problem is somewhere in the axles. Bad wheel bearing, diff bearing, R&P, R&P bearing, or mainshaft bearing.

And Bruce's comment about the bearings wasn't useful? You're going to need a couple special sockets for removing specific nuts within the tranny, a couple different sets of snap ring pliers, a jig to reset the shifting forks, and a press. Typically between $500-$1000 worth of tools, and that's not counting any replacement parts, or instructional video's on how to do it. The usual samba user get's their tranny repaired by a competent shop for less than the cost of the tools, then there's no chance of them screwing it up. If you do decide to try, and do the work yourself, you're not going to find it's a shifting fork that's making the noise.

Sun Feb 12, 2012 10:02 pm

dead mounts or any thing tuching the chassie/body that isant supposed to or is supposed to be isolated will make noisethat you can hear but isant realy there,well it is but it is normaly isolated so you dont hear it.
I think I will start trying to get into the trans stuff I have 3 dead ones, 1 new rino superstreet pluss rancho.& 1 unknown.Ive done hundrads of trans,automatic &std,plenty of rearends, just no vw yet.I reckon I need to get a book or cd befor I just tear it appart,althou I am pretty sure I could do it with out it Im not going to try.get what you need before scattering it appart. is the shift bushing dead??

Sun Feb 12, 2012 11:17 pm

Jigs from Geno 50$, pinion socket 110$, small and large circlips 30$, etc. Hardest tool to get is a press. Luckily i got one at work. Videos from long enterprises 70$. Im attempting my first rebuild on a stock 4.37 to a 4.12 and 3.78 mainshaft. I'm getting a new mainshaft bearing, new superdiff and new synchros too. Today I cleaned the case in and out, cleaned the side cover ( got a hd sidecover already , gaskets and new German boots. Will be soda blasting the tubes than paint everything probably sometime this coming week. I think its doable if you put your mind to it anythings possible to fix. Just about.

Sorry forgot to mention props to Bruce, Geno, and Rich Robertson for the help to date. Aircooleds are so cool.

Mon Feb 13, 2012 3:05 am

Sockets I have, snap-ring pliers I have, a press I can borrow from a friend with a machine shop. Advice that no one but armchair hicks can be found on this forum I found less than useful. Bruce, Geno, and Rich have my gratitude. The wheel bearings are not the issue, my ignorance of the inside of a late model transmission is my primary impediment.

Apologies to any I may have offended in my search for illumination.

Mon Feb 13, 2012 7:59 am

Harleyelf wrote: Sockets I have,

The socket Jfats is referring to is the giant pinion socket. There's nothing else that fits the pinion nut (if you can call it a nut, it's more like a big internally threaded ring with teeth on the OD) except a tool that's made for it. I think they started using that style pinion retainer in 69 or 70. I know my 70 DSC trans had it.

Mon Feb 13, 2012 8:59 am

T-1 70 and later use the late pinion nut( easy to id, only 1 drain plug, rhino and autocraft the exeption) all 002 and later t-2 trans use the late nut as well.

Mon Feb 13, 2012 3:59 pm

And that special socket is $135.00 http://vwparts.aircooled.net/Pinion-Retaining-Nut-Socket-1969-p/7065-25.htm

Oh and you'll also need a jig to reset the shift forks. http://vwparts.aircooled.net/TRANS-A-JIG-Transmission-Tool-Kit-p/7065-20.htm

Mon Feb 13, 2012 4:24 pm

If you need to change synchros and reset the forks, a jig can be made using an old trans case with the side cut out.
As to the pinion nut, you can try a blunt chisel or block of hardwood and tap it off, or, I made a "socket" from the right size PVC pipe , I think it was 3", cut to about 6" long. Screw a pipe plug with a square drive on it into one end. Carefully soften the inner edge of the other end with heat gun or propane. When its soft enough to press a screw driver into it, place it over the big ring nut and hammer it onto the nut to form it to the nut. You now have a socket that will turn the nut if you use care. It's not metal but it costs a lot less.
These are hard days. You gotta do what ya gotta do.